Makes hidden entity loaders accessible. Rewritten add-loader with new loader snapping logic and graphics.

Bug Reports outside Forum or Github will be ignored!

Features:

• Graphics from Arch666Angel, updated by Kirazy.
• Rebalanced recipes to cost slightly less than fully upgraded inserters/stack inserters required for same chest>belt throughput.
• Loader Snapping works for all belt entities.
• API for creating loaders including sprites and icons: https://github.com/0ptera/Loader-Redux#readme

Credits:

kij336 - add-loader
Arch666Angel, Kirazy - graphics
Nexela, ReverseStateMonad - train worker rewrite
Articulating - original Loader Snapping